RGMAP

        [GREG2\]RGMAP [Quiet|Fast|chunksize] [/PERCENT  P1]  [/ABSOLUTE  A1]
    [/BLANKING  Bval Eval] [/GREY COLOUR N] [/KEEP File_Name [Blank]] [/PENS
    [Pos Neg]] [/ONLY POSITIVE|NEGATIVE]

    Draws (or fills) isocontours of the Regular Grid array. The RG is an in-
    ternal  2D "map" created/loaded by various commands (RGDATA, RANDOM_MAP,
    RESAMPLE, IMAGE), or loaded by a calling program. The levels  are  those
    specified  by command LEVELS, but may be affected by a scaling factor by
    option /PERCENT or /ABSOLUTE.

    This command is normally used in the following sequence:
    Greg> SET BOX LOCATION Gx1 Gx2 Gy1 Gy2  ! Define box position
    Greg> RGDATA (options...)               ! Put image in the RG variable,
                                            ! read associated header variables
    Greg> LIMITS /RGDATA                    ! Computes associated limits
    Greg> PLOT                              ! Plot the array in the box
    Greg> BOX                               ! Draws the box
    Greg> LEVELS 0.1 to 0.9 by 0.1          ! define contour levels
    Greg> RGMAP /PERCENT 1                  ! Draw contour levels  (in this
                                            ! case, as percentage of peak)

    The "Quiet" mode does contouring silently. For  "Fast"  and  "chunksize"
    modifiers, see subtopic MEMORY_OPTIONS.